JP2594596Y2 - Optical deflector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical deflector for deflecting light by using a tuning fork vibrator having a predetermined amplitude.

[0002]

2. Description of the Related Art For example, there is an optical laser scanning type external shape measuring instrument for measuring an external shape in a non-contact manner with high speed and high accuracy. A tuning fork vibrator for obtaining a predetermined amplitude is used in the external shape measuring device. Conventionally, as shown in FIG.
2 is a U-shaped metal round bar to form a fork 23, and a support bar 24 is welded to the base end of the fork 23 by brazing or the like. Further, a reflector 25a made of glass is soldered to one end of the U-shaped fork portion 22, and a balance is applied to the other end,
A reflector (balancer 25b) having the same shape as the reflector 25a attached to one end is attached by soldering or the like.

As shown in FIG. 6, there is a tuning fork vibrator 26 which is not a round bar but is cut out from a flat plate by cutting or the like, and has a square cross section. This is fork 2
The reflector 7a and the balancer 29b are soldered to the tip of the fork 27 in the same manner as the tuning fork vibrator 22 of a round bar. In the tuning fork vibrator 26, a fork 27 is a vibrator having a unique frequency with respect to a support rod 28 to be fixed, and an electro-magnetic converter such as an electromagnetic coil is provided near the fork 27 to provide a fork. 27 is flexed and vibrated. The tuning fork vibrator 26 is characterized by having a high Q flexural vibration, and is used for an optical deflector or the like. The optical deflector is incorporated in an external shape measuring device, and is used for applications such as measuring the external shape of an object to be measured by reciprocating scanning of light.

FIG. 4 is a view showing the principle of an optical deflector using a tuning fork vibrator S. As shown in FIG.
In the case where the reflector 3 is provided at the tip of a and the incident light A is incident from a certain direction, the outgoing light B is deflected at the deflection angle θ as shown in FIG. Here, f is the lens 21
And the deflection width f of the tuning fork vibrator S
θ is determined by the product of the deflection angle θ and the focal length f. The ratio of the spot diameter D of the light to the total deflection width W, D / W, is the resolution of the optical deflector. The larger the deflection width, the higher the resolution and the performance. Therefore, there is a demand to increase the magnitude of the bending vibration of the tuning fork vibrator S, and a demand to increase the deflection width fθ in the optical deflector.

[0005]

However, the round bar tuning fork vibrator 22 is bent in order to form the fork portion 23 into a U-shape, but it is difficult to obtain an accurate angle and length. . Further, since the bending stiffness of a round bar is not directional, the deflected light may be elliptical. In addition, since the fork portion 23 and the support rod 24, or the fork portion 23 and the reflector 25a and the balancer 25b are composed of separate parts, it is difficult to position them when assembling them by welding or soldering. Heat reduces the strength of the material. Further, since the reflector 25a and the balancer 25b are soldered to the vibrating portion, it is necessary to strictly control the quality of the soldering. For these reasons, the fork portion 23 that vibrates at a high frequency cannot obtain a large deflection angle of the flexural vibration, has a poor directionality of the deflection, and has a large number of manufacturing steps.

A tuning fork vibrator 26 formed by cutting out a flat plate is an improvement on the above point.
When soldering the reflector 7 to the reflector 29a and the balancer 29b, the problems of difficulty in positioning and the necessity of controlling the quality of soldering could not be solved.

The present invention has been made in view of such circumstances, and its purpose is to prevent the strength from decreasing and improve the directionality of vibration by integrating the shape of the tuning fork vibrator. An object of the present invention is to provide an optical deflector that can increase a deflection angle and a deflection width and that has high quality and requires a small number of manufacturing steps.

[0008]

In order to solve the above-mentioned problems, an optical deflector according to the present invention has a fork formed in a U-shape, a support extending continuously to a base end of the fork, and a reflection pair. And a balancer are formed at respective ends of the fork portion, and a tuning fork vibrator is provided in which the fork portion, the support portion, the reflector, and the balancer are integrally formed. Further, in the optical deflector of the present invention, the fork portion is formed in a U-shape, the support portion is continuously extended to the base end of the fork portion, and the balancer is continuously formed at one end of the fork portion. A tuning fork vibrator in which a portion, a support portion, and a balancer are integrally formed, and a reflector is attached to the other end of the fork portion.

[0009]

Since the fork, the support and the reflector of the tuning fork vibrator of the present invention are integrally formed, the accuracy of each position and angle is good, and the directionality of vibration is improved. In addition, since heat such as welding is not applied, a decrease in strength of the tuning fork vibrator can be prevented. Therefore, the optical deflector using this tuning fork vibrator can obtain a large deflection angle, and can greatly reduce the number of manufacturing steps.

[0010]

FIG. 1 is a perspective view showing a first embodiment of the present invention. The fork 1 of the tuning fork vibrator S is formed in a substantially U-shape, and the tips of the forks 1a and 1b extending in parallel are formed in a T-shape as the reflector 3 and the balancer 4. It is desirable that the reflector 3 and the balancer 4 have the same shape in order to satisfy the function as a tuning fork.
Each has the same shape front-end | tip plane 3a, 4a. The tip flat surface 3 a is mirror-finished and has characteristics as the reflector 3.

A support portion 2 for fixing the tuning fork vibrator S is formed at a substantially U-shaped base end of the fork portion 1. The support portion 2, the fork portion 5 reflector 7, and the balancer 8 are integrally formed. It is formed. For example, the tuning fork vibrator S is integrally formed by cutting a flat metal plate (SK material in this embodiment).

FIG. 2 shows a second embodiment of the present invention. Fork part 5, support part 6, and balancer 8 of tuning fork vibrator S
Has the same configuration as in the first embodiment, but the reflector 7 is attached to the tip of one of the forks 5a by soldering.

Next, an optical deflector using the above-described tuning fork vibrator will be described. FIG. 3 is a diagram showing an outline of the optical deflector 9. The support portion 2 of the tuning fork vibrator S is fixed to the device housing. A reflector 3 having a mirror surface for total reflection is formed at the tip of the fork portion 1a of the tuning fork vibrator S. The tuning fork vibrator S is excited by an electromagnetic coil 11 provided near the fork portion 1a, and generates a predetermined vibration.

The incident light A from the light emitting source 10 is incident on the reflector 3 at a predetermined angle. On the optical path of this reflector 3,
A lens 13 is provided, and the lens 3 converts the light into desired light such as parallel light. This reflected light B is converted into light by a lens 14 by a light splitting means 12 such as a half mirror.
After being made parallel light between a and 14b, the light is detected by the photodetector 16. A knife edge 19 is provided in the optical path before the lens 14b. Therefore, the detection signal of the photodetector 16 becomes a signal of a predetermined cycle with respect to the resonance frequency due to deflection described later. In front of the knife edge 19, a light splitting means 15 such as a half mirror is provided. The split light scans a fixed gauge 20 having a fixed size. Is detected. These detection signals are output to the comparator 18.
The frequency of the electromagnetic coil 11 is controlled in accordance with the period of the detection signal by the signal output from the comparator 18 and the deflection thereof is controlled to be constant.

Next, the operation of the above configuration will be described. The fork portion 1b of the tuning fork vibrator S excited by the electromagnetic coil 11 vibrates at a predetermined bending angle. As a result, the reflector 3 at the tip of the fork portion 1a deflects the incident light A at a deflection angle θ having a predetermined amplitude and emits it as emission light B.

[0016]

[Effect of the Invention] Since the fork portion, the support portion, the balancer and the reflector of the tuning fork vibrator of the present invention are integrally formed, there is no need to manufacture the reflector separately, and work such as welding for assembly is unnecessary. And the accuracy of each position and angle is improved, thereby improving the directionality of vibration. For this reason,
When the tuning fork vibrator is mounted, it is not necessary to adjust the deflection direction, and the time required for assembly is reduced. In addition, since the heat of welding or the like is not applied, a decrease in the strength of the tuning fork vibrator can be prevented, and the optical deflector using this tuning fork vibrator can obtain a large deflection angle. Also, by integrally forming the fork, support, and balancer, and manufacturing only the reflector separately,
The reflectors having different sizes are prepared, and the assembly is performed only by attaching the reflectors on one side, and it is possible to easily cope with the change of the reflectors.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a tuning fork vibrator of the present invention.

FIG. 2 is a perspective view showing another embodiment of the tuning fork vibrator of the present invention.

FIG. 3 is a schematic view showing the optical deflector of the present invention.

FIG. 4 is a diagram showing a state of light deflection using a tuning fork vibrator.

FIG. 5 is a perspective view showing a conventional tuning fork vibrator.

FIG. 6 is a perspective view showing a conventional tuning fork vibrator.

[Explanation of symbols]

 1 Fork section. 2 Support. 3 Reflector. 4 Balancer. 5 Support. 6 Fork section. 7 Reflector. 8 Balancer. 9 Optical deflector. 10 Emission source. 11 Electromagnetic coil. 12 Light splitting means. 13 lenses. 14 lenses. 15 Light splitting means. 16 Photodetector. 17 Photodetector. 18 Comparator. 19 Knife edge. 20 Fixed gauge. 21 lenses. A Incident light. B Emitted light. D Spot diameter. f Focal length. θ deflection angle. S Tuning fork vibrator. W Total deflection width.

Claims (2)

(57) [Scope of request for utility model registration] 1. An optical deflector (9) for deflecting incident light (A) by bending of a generally U-shaped tuning fork vibrator (S) to emit outgoing light (B), A fork part (1) formed substantially in a U-shape, a support part (2) extending continuously to the base end of the fork part, and a reflection formed at one end of the fork part (1). A body (3); and a balancer (4) formed at the other end of the fork (1). The fork (1), the support (2), the reflector (3), and An optical deflector characterized by being integrally formed with a balancer (4). 2. An optical deflector (9) for deflecting incident light (A) by bending a generally U-shaped tuning fork vibrator (S) to emit outgoing light (B), A fork part (1) formed in a substantially U-shape, a support part (2) extending continuously from the base end of the fork part, and a balancer formed at one end of the fork part (1). (8), a reflection pair (7) is provided at the other end of the fork (1), and the fork (1), the support (2), and the balancer (8) are integrally formed. An optical deflector characterized by the above-mentioned.